eobertson



(No Model.) 7 2 Sheets-Sheet 1. J. H. ROBERTSON.

WRITING TELEGRAPH No. 543,426. Patented July 23, 1895.

(Nd Model.) 2 Sheets--S11eet' 2,

J. H. ROBERTSON.

WRITING TELEGRAPH.

No. 543,426. Patented July 23, 1895.

Wflmesses 3 Invenibr: kwAQ UNITED STATES PATENT OFFICE.

JAMES HART ROBERTSON, OF BROOKLYN, NEW YORK, ASSIGNOR, TO

WILLIAM E. GUMP, OF SAME PLACE.

WRlTl NG-TELEG RAPH.

SPECIFICATION formingpart of Letters Patent NO; 543,426, dated. July 23,1 895. Application filed December 19, 1 894. fierial No. 532,376- (Nomodel.)

To all whom it may concern:

Be it known that I, J MES HART ROBERT- SON, a citizen of the UnitedStates, and a resident of Brooklyn, in the county of Kings and State ofNew York, have invented certain new and useful Improvements inWriting-Telegraphs, of which the following is a specification.

My invention relates to writing-telegraphs.

The object of my invention is to construct a receiving-pen elevating andlowering mechanism which will not require any additional line-wire forits operation, and which is operated by an induced current. I accomplishthis obj ectby the means hereinafter described and claimed.

In the accompanying drawings, forming part of this specification, Figure1 is a diagrammatic view of a pen elevating and lowering mechanismembodying my invention. Fig. 2 is a detail view of the armature-leverfor lifting the pen. Figs. 3 and 4 illustrate a modification of myinvention- Referring to the drawings, 1 and 2 indicate, respectively,the transmitter and receiver of a writing-telegraph, while 3 4 are thetwo linewires connecting the same, and 5 the operating-battery. Thereceiver and transmitter may be such as shown in my Patent No. 353,593,dated November 30, 1886,and further illustration or description thereofis not, therefore, necessary in this specification.

A local battery, At the receiver I bridge the main conductors with aconductor 12, and arrange in the latter a condenser 13 and polarizedmagnet 14. The pivoted armature 15 of this magnet is provided with anarm 16, carend of the armature-rod 19, and rests normally on the paperon the table 20. p

The operation of the mechanism is as follows: When the operator at thetransmitter desires to lift the pen at the receiver he closes thecircuit-breaker 8 and thus sends an induced current over the line, saidcurrent being induced in the secondary wire of the induction-coil. Thecurrent or impulse thus generated passes through cond'enser7 to mainlineconductor 3, through condenser 13, condoctor 12, polarized magnet 14 andremainder of conductor 12 to main conductor 4, and from thence back tosecondary wire 10 of induction-coil. The current thus passed throughpolarized magnet 14 draws the forward end 21 of the armature 15downward, thus moving arm 16 forward at its upper end and lifting thereceiving-pen 18 from the writing-table,

the pen meanwhile having free movement on the surface of finger 17. Whenthe operator desires to lower the pen, hereleasesthe circuit-breaker,which breaks the primary circuit of the induction-coil, and thus aninduced current of opposite polarity to the first one is sent over theline and the armature 15 is attracted at its right-hand end and broughtback to the position shown in Fig. 1, thus allowing the receiving-pen toagain rest on the writingtable. The condensers 7 and 13 prevent themain-battery currents from affecting or operating polarized magnet 14,and it is evident that such battery-currents may be either intermittentor undulatory. magnet 14 is preferably higher as compared with themagnets of receiver 2. The induced current will of course divideaccording to ohms "law, but enough will pass through the The resistanceof polarized magnet 14 to operate its armature,

and the remainder that passes through the receiver-magnets will not besufficient to affect the receiver-armature on account of the IOOductors, a circuit-breaker 23 and local battery 24, the same as in theconstruction shown in Fig. 1, but I omit the condenser in'the secondarywire and make the latter of sufficientlyhigh resistance, relatively, tothe resistance of the main conductors, to prevent the pas sage of enoughbattery-current to interfere with the proper working of the system.

It is evident, of course, if only one mainline conductor were usedbetween receiver and transmitter, that the operation of the inducedcurrent would be the same as when two main conductors were used, for inthe former case one terminal of the secondary wire of theinduction-coilwould be connected with the main line, while the other terminal would beconnected to ground.

At the receiver I bridge the main conductors 26 and 27 with a condenser28 and polarized relay 29 before said main conductors are connected tothe receiver-magnets. Arranged in connection with the armature 30 of thepolarized relay is a local circuit 31, in which is placed alocal battery32 and a penlifting magnet-33, the pivoted armature 34 of which isprovided with an arm 35 and finger 36 for lifting the pen, substantiallythe same as shown in Figs. 1 and 2. By this mechanism the comparativelyweak induced current closing the local circuit is thereby in effectreinforced. The main battery impulses or currents sent over the mainlines will, to a certain extent, charge the condenser 28, but to such asmall extent as not to influence the relay in circuit therewith. When aninduced current is sent over the line by closing or opening the primarycircuit of the inductioncoil at the transmitter, the high electromotiveforce thereof will cause it to pass through the condenser and operatethe relay, which in turn closes or opens the local circuit at thereceiver, the mechanism of which directly effects the lifting of thepaper.

In Fig. 3 the transmitter is designated as 1 and the receiver as 2, thesame as in Fig.1.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. In a writing telegraph, the combination with the receiver andtransmitter, and electrical connection between the same, of a penlifting and loweringmechanism, and an induced current generatingmechanism arranged to operate, through the said electrical connection,the said pen lifting and lowering mechanism, substantially as described.

2. In a writing telegraph, the combination with the receiver andtransmitter, and the main line conductors connecting the same, of a penlifting and lowering mechanism and an induced current-generatingmechanism arranged to operate, through said main line conductors, thesaid lifting and lowering mechanisnnsubstantially as described.

3. In a writing telegraph, the combination with the receiver andtransmitter, and electrical connection between the same, of an inductioncoil, circuit closer, and local battery, arranged at the transmitter,and a condenser, and pen-lifting mechanism arranged at the receiver bothmechanisms at transmitter and receiver being connected by conductors tothe electrical connection between transmitter and receiver,substantially as described.

4:. In a writing telegraph, the combination with the receiver andtransmitter, and the main conductors connecting the same, of aninduction coil circuit-breaker, and local battery, connected to saidconductors at the transmitterfand a condenser, polarized relay, localbattery circuit, pen lifting magnet, and pen lifting armature arrangedin connection with the main conductors at thereceiver, substantially asdescribed.

5. In a writing telegraph, in combination, a condenser,polarized magnetand pen-lifting mechanism in a local circuit arranged be tween the twoline wires at the receiver, substantially as described.

6. In a writing telegraph, the combination with the receiving pen, of anarmature arranged to lift and lower said pen and an electro magnetoperating said armature and connected with the main line conductorsthrough a condenser, substantially as described.

Signed at New York, in the county of New York and State of New York,this 13th day of November, A. D. 1894.

JAMES HART ROBERTSON.

NVitnesses:

J. E. M. BOWEN, M. O. PINcKNEY.

